There is a constant demand for vapor lock sealed containers for many industrial uses. These uses include storage and shipping of such diverse materials as paint, clams, pickles, mastics, vinyl adhesives, automobile dent filler, caulking compounds, swimming pool chemicals, mayonnaise, peanut butter, and many other liquids, pastes and solids. For most of these applications it is important that the lid be securely retained on the container body and form an air-tighte closure therewith. It is also important that the closure be removable and resealable enough times to permit use of the contents without destruction of the air tight seal.
For some of these applications, metal-paint cans have been used. These cans normally have an upwardly open groove formed in the upper portion of the body thereof into which a lip on the can is inserted. This type of container has a number of draw backs, including the fact that the air-tight seal is often deformed as a result of the opening of the can with a screwdriver or other similar device. In addition, the groove formed in the container retains any materials which fall into it, which materials, upon hardening, make an air tight closure almost impossible. If the top is pressed on before the materials harden, they often squirt out unto the user of the container or the floor. There are containers available which have a receiving groove formed on the closure, and thereby avoid some of the problems of the usual paint can type of container. Examples of this type of container are disclosed in U.S. Pat. No. 4,004,710; U.S. Pat. No. 4,079,857; and U.S. Pat. No. 4,078,696, all by the present inventor Victor Eugene Crisci.
The containers disclosed in these three patents are generally the type of container with which the present invention is concerned, however, these containers do not utilize the combination clamping and wedging action of the present invention to attain a vapor locked seal forming four separate contact surfaces.
U.S. Pat. No. 4,004,710, provides a fluid-tight seal between the container and the lid by peripheral contact under pressure between a convex inner edge of the container lip and a splayed surface within a peripheral, inverted U-groove in the lid. Sealing pressure is provided by co-action between complimentary sloping surfaces on the container lip and within the lid peripheral groove respectively which tends to draw the lid in a closing direction. As can be seen in FIG. 2, this provides two diametrically opposed contact surfaces with a relatively large clearance space therebetween. U.S. Pat. No. 4,078,696 features a resilient seal in the form of an O-ring gasket 11 which, as can be seen by comparing FIGS. 2 and 3, is deformed to form a closure seal. The device shown in this patent is otherwise similar to the one shown in U.S. Pat. No. 4,004,710, and is intended to obtain a positive seal and position seat for such a closure. U.S. Pat. No. 4,079,057, teaches a closure with three contact surfaces with a space formed between the fourth surfaces.